Resources
San Diego HVAC glossary
The HVAC words that show up on quotes, permits, and rebate forms. Live SDG&E amounts belong on sdge.com/rebates. The federal 25C credit does not apply to equipment placed in service in 2026. TECH single-family HVAC reservations stopped November 14, 2025. HEEHRA single-family was fully reserved February 24, 2026.
Equipment and terms
- SEER2
- Seasonal Energy Efficiency Ratio 2, the 2023+ efficiency metric for AC and heat pumps. California minimum is 15 SEER2 split systems; federal Inflation Reduction Act rebates require 16+ SEER2.
- Manual J
- ACCA's residential heating and cooling load-calculation standard. Running Manual J is how a contractor determines the correct equipment size for your specific home, oversizing wastes money, undersizing fails to cool in peak heat.
- Heat pump
- System that both heats and cools using a refrigerant cycle, replaces a separate AC and gas furnace. Often the best fit for San Diego's mild climate. Rebate availability changes year to year, so confirm current SDG&E and state programs before you count on a number.
- Ductwork R-value
- Insulation rating of supply/return duct. California Title 24 requires R-8 minimum in unconditioned attic space, older homes often have R-4.2 that fails current code.
- MERV rating
- Minimum Efficiency Reporting Value, filter efficiency rating from 1-16. MERV 13 is the sweet spot for residential IAQ without over-restricting airflow.
- Condensate line
- PVC drain that carries evaporator-coil condensate to the exterior. Clogs cause backup, ceiling damage, and system shutoff, annual flush is basic maintenance.
- Short cycling
- When a system runs for under 10 minutes then shuts off repeatedly. Usually indicates oversized equipment, low refrigerant, or failing capacitor. Accelerates compressor failure.
Materials and refrigerants
- R-454B
- The low-GWP refrigerant replacing R-410A in 2025+ residential HVAC equipment per EPA rules. Mildly flammable (A2L class), technicians need updated leak-detection equipment.
San Diego specifics
- Marine layer
- Coastal fog + humidity affecting the western third of SD County from May-September. Keeps outdoor temps mild but raises indoor humidity loads. Most coastal HVAC systems benefit from dehumidification integration.
- Santa Ana winds
- Dry, hot easterly winds in fall/winter that push inland temps well above the seasonal normals and drop humidity below 10%. Forces AC systems to run hard during what's supposed to be shoulder season.
- SDG&E EV-TOU-5
- San Diego Gas & Electric's time-of-use rate plan for EV owners, heavily discounted 12am-6am super-off-peak pricing makes nighttime pool, AC pre-cooling, and EV charging cost-effective.
Licensing
- C-20 HVAC
- California CSLB Class C-20, Warm-Air Heating, Ventilating & Air-Conditioning. Required for system installation, refrigerant handling, ductwork modification, and most permitted HVAC work.
Serving San Diego County
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